Fasting and IBD

What is fasting?

Fasting is abstaining from eating for a period of time.

We all usually naturally fast for a period of time overnight and often for short periods of time during the day between meals.

There are instances where people may fast for longer periods. There are usually two reasons for this. One being for religious reasons - Ramadan is observed by Muslims every year as a holy month and a time of fasting. And the other for weight loss or potential health benefits.

There are many different fasting diets that have become trendy over the past few years these include the 5:2 Diet (limits calorie intake 2 days a week), 6:1 diet (usual eating 6 days per week and a 24 hour fast 1 day a week) alternate day fasting, 16:8 Method (fasting for 16 hours a day and consuming meals within an 8 hour window), to name just a few.

 

Fasting and IBD

Currently, there is very little research on fasting specifically in Crohn’s and Colitis. A couple of animal trials have shown there may be some benefit but whilst studies in animal models of IBD can provide interesting information and inform direction of further research in humans, we cannot take animal trial findings as gospel as sometimes the findings in humans differ as we are different species (1,2).

Retrospective data in humans, looking at people with IBD who were hospitalised and either fasted or received food, suggested fasting was not effective in decreasing disease activity (3).

Researchers at Cornell University in the USA are currently recruiting for a small trial to look at the impact of time restricted feeding in Crohn’s Disease in humans (4) which may help to give us some more information.

 

Potential benefits of fasting:

  • May help aid weight loss if someone is overweight or obese.

  • Bowel rest may alter bacteria in the intestines (microbiota) and reduce common foods that irritate the inflamed intestine which may lead to a decrease in inflammation (5).

 Potential Drawbacks:

  • Lack of evidence and no significant differences between fasting and calorie restriction for weight loss.

  • May increase weight loss which may not be desired in someone already underweight with IBD.

  • May increase risk of nutrient deficiencies which is already high in IBD.

  • May lead to tiredness, headaches, lack of concentration and poor mood, all symptoms already associated with IBD.

  • May promote disordered eating behaviours which some people already experience in IBD.

  • May put extra unnecessary stress on the body and person with IBD.

  • May not be possible if you take medication that has to be taken with food as specific times of the day.

 

Safety of fasting with IBD

Fasting is probably safe in most people with IBD. But it may not be safe if:

  • You have high fluid losses – either because you have an ileostomy that gives a high-volume output (more than 1.5 litres per 24 hours), or because of high losses from a fistula (a connection from the bowel to the abdominal wall) that has similar high output, or severe diarrhoea

  • You have severe malnutrition, or you cannot eat a large meal in a short time

  • You have very active disease and have severe pain, fever, fatigue, vomiting or diarrhoea

  • You need to take medication by mouth during the fasting period or with food (6).

Take Away

Fasting for Ramadan is considered safe for most people with IBD but may be unsafe in a small number of people with high fluid losses or active disease. If you are not sure, please check with your IBD team.

Whilst anecdotally some people may have found fasting helpful for their IBD, at the moment, we do not have nearly enough evidence about the safety and efficacy of fasting in IBD to be recommending it for health improvement purposes. The risks of fasting with IBD very much outweigh the positives currently due to increasing risk of nutrient deficiencies and promotion of disordered eating behaviours.

 

References

  1. Rangan P, Choi I, Wei M, Navarrete G, Guen E, Brandhorst S, Enyati N, Pasia G, Maesincee D, Ocon V, Abdulridha M, Longo VD. (2019) Fasting-Mimicking Diet Modulates Microbiota and Promotes Intestinal Regeneration to Reduce Inflammatory Bowel Disease Pathology. Cell Rep;26(10):2704-2719.e6. doi: 10.1016/j.celrep.2019.02.019.

  2. Zhang, X., Zou, Q., Zhao, B., Zhang, J., Zhao, W., Li, Y., Liu, R., Liu, X., & Liu, Z. (2020). Effects of alternate-day fasting, time-restricted fasting and intermittent energy restriction DSS-induced on colitis and behavioral disorders. Redox biology, 32, 101535. https://doi.org/10.1016/j.redox.2020.101535

  3. Park, Y. et al, (2020) Is fasting beneficial for hospitalized patients with inflammatory bowel diseases? Intest Res;18(1):85-95. DOI: https://doi.org/10.5217/ir.2019.00055

  4. US National Library of Medicine - Clinicaltrials.gov (2021) The Impact of Time Restricted Feeding in Crohn's Disease (TRF-CD). Available at: https://clinicaltrials.gov/ct2/show/NCT04271748 (Accessed 15 March 2021)

  5. Lochs, H (2010) Basics in Clinical Nutrition: Nutritional support in inflammatory bowel disease. e-SPEN, the European e-Journal of Clinical Nutrition and Metabolism. 5(2). Pages e100-e103. https://doi.org/10.1016/j.eclnm.2009.06.009.

  6. Crohns & Colitis UK (2020) Ramadan: Tips for Fasting with Crohn’s and Colitis. Available at: https://www.crohnsandcolitis.org.uk/news/ramadan-tips-for-fasting-with-ibd#:~:text=Will%20fasting%20put%20my%20IBD,diarrhoea%20%E2%80%93%20improve%20on%20stopping%20eating. (Accessed 15 March 2021)

Clemmie Macpherson